Ferroelectric element and method for manufacturing the same
View Patent ↗In a ferroelectric element, the ferroelectric film is prevented from deteriorating and the interconnect film from lowering in reliability. A ferroelectric element comprises a first electrode, a ferroelectric film formed on the first electrode, a second electrode formed on the ferroelectric film, a first hydrogen blocking film formed directly on a surface of the second electrode, a first insulation film formed on the first hydrogen blocking film, a first opening formed in the first hydrogen blocking film exposing a part of the second electrode, a second opening formed in the first insulation film and having a greater diameter than the diameter of the first opening, and an interconnect film connected to the second electrode through the first and second openings.
1. A ferroelectric element comprising:
a first electrode;
a ferroelectric film formed on the first electrode;
a second electrode formed on the ferroelectric film;
a first hydrogen blocking film formed directly on a surface of the second electrode;
a first insulation film formed on the first hydrogen blocking film;
a first opening formed in the first hydrogen blocking film and exposing a part of the second electrode;
a second opening formed having a greater diameter than a diameter of the first opening, in the first insulation film; and
an interconnect film connected to the second electrode through the first and second openings.
2. A ferroelectric element according to claim 1 , wherein the first and second openings each have a diameter substantially constant with respect to the axial direction thereof.
3. A ferroelectric element according to claim 2 , wherein the first and second openings are formed by different processes from each other.
4. A ferroelectric element according to claim 3 , wherein the first opening is formed in the hydrogen blocking film prior to forming the first insulation film.
5. A ferroelectric element according to claim 2 , wherein the first opening has an aspect ratio of 1 or smaller.
6. A ferroelectric element according to claim 1 , wherein the first and second openings are formed to have a diameter increasing with distance from the second electrode.
7. A ferroelectric element according to claim 6 , wherein the first and second openings are formed in one process.
8. A ferroelectric element according to claim 6 , wherein the first insulation film has a second hydrogen blocking film formed at the second opening and a second insulation film formed around the second hydrogen blocking film.
9. A ferroelectric element according to claim 8 , wherein the first and second openings are formed in a self-aligned fashion by etching back.